Blackstone (BX) employee was one among four people killed Tuesday in New York when a gunman opened fire, according to multiple reports citing police officers.

The gunman, who also killed himself, reportedly had a fixation on Chronic Traumatic Encephalopathy, a condition caused by head trauma, the reports added.

His social media posts indicated that his football career ended due to a head injury and that he felt the NFL did not do enough for him, the reports added.

Blackstone didn't immediately reply to MT Newswires' request for comment.